1. Field of the Invention
The invention relates generally to connectors and more specifically to an insulation piercing connecting device. The clamping slot made of flat material with at least two clamping legs between which a clamping slot extends essentially in the longitudinal direction of the device is formed by a shearing cut. An insulated connecting wire can be pushed into the slot so as to produce a contact. The slot has at its free end, a constriction for retaining the connecting wire in the clamping slot.
2. Background of the Related Art
An insulation piercing connecting device of this kind has been disclosed for example in DE 27 08 841 C2. According to this, a rounded-off small projection which, in the vicinity of the free end, projects into the clamping slot, is formed on one of the clamping legs by crowding. This projection makes it more difficult to pull out the connecting wire which is otherwise held by friction only. In particular, the projection prevents the connecting wire from loosening, for example when vibration occurs.
Insulation piercing connecting devices of this kind are required in large numbers in terminal strips. The thin punch which performs crowding is subject to a high degree of wear which requires frequent changing with subsequent re-adjustment of the deformation depth. Punches made of harder material are correspondingly more brittle and are more likely to fracture.